The Skeletal System

1. The Skeletal System

2. The Axial Skeleton • Forms the longitudinal part of the body • Divided into three parts • Skull • Vertebral column • Bony thorax • And…. Also Hyoid Bone

3. The Axial Skeleton Figure 5.6

4. The Skull • Two sets of bones • Cranium • Facial bones • Bones are joined by sutures • Only the mandible is attached by a freely movable joint

5. The Skull Figure 5.7

6. Bones of the Skull Figure 5.11

7. Human Skull, Superior View Figure 5.8

8. Human Skull, Inferior View Figure 5.9

9. Paranasal Sinuses • Hollow portions of bones surrounding the nasal cavity Figure 5.10

10. Paranasal Sinuses • Functions of paranasal sinuses • Lighten the skull • Give resonance and amplification to voice Figure 5.10

11. The Hyoid Bone • The only bone that does not articulate with another bone • Serves as a moveable base for the tongue Figure 5.12

12. The Fetal Skull • The fetal skull is large compared to the infants total body length Figure 5.13

13. The Fetal Skull • Fontanelles – fibrous membranes connecting the cranial bones • Allow the brain to grow • Convert to bone within 24 months after birth • Called “Soft Spots” Figure 5.13

14. The Vertebral Column • Vertebrae separated by intervertebral discs • The spine has a normal curvature • Each vertebrae is given a name according to its location Figure 5.14

15. Structure of a Typical Vertebrae Figure 5.16

16. Regional Characteristics of Vertebrae Figure 5.17a–b

17. Regional Characteristics of Vertebrae Figure 5.17c–d

18. The Bony Thorax • Forms a cage to protect major organs Figure 5.19a

19. The Bony Thorax • Made-up of three parts • Sternum • Ribs • Thoracic vertebrae Figure 5.19a